1. Field of the Invention
The present invention relates to systems which are designed to account for fluids being dispensed from a fluid container, and in particular is designed to monitor the amounts of beverages, such as draft beer, which are dispensed in varying quantities.
2. Description of the Prior Art
Numerous systems have been developed in the past for measuring and totalizing the amount of a fluid dispensed from a container of the fluid. Typically, such arrangements employ a mechanical element, such as a rotor, in the fluid flow path in order to measure the amount of fluid dispensed based upon the actual flow rate out of the container. Conventional gasoline pumps are an example of these types of prior art systems. Another example is disclosed in U.S. Pat. No. 3,780,579 to Barnard.
Such arrangements have not proven satisfactory in dispensing beverages because of the bulkiness of the required structures and the inherent cost. Accordingly, electronic systems have been developed for the purpose of monitoring the dispensing of beverages.
In U.S. Pat. No. 3,965,337, Young discloses a draft beer monitoring system in which the amount of beer dispensed is displayed as a function of dollars and cents. As disclosed by the patentee, the monitor may be switched between glass and pitcher rate monitors.
In U.S. Pat. No. 3,665,167, Goodwin discloses a system similar to that disclosed in the aforementioned patent to Young, in that the output is measured in monetary quantities.
In U.S. Pat. No. 3,699,315, Upton discloses a monitor for fluid dispensers in which accountability is dependent upon the amount of price per unit volume.
The manner in which draft beer is customarily sold creates particularly unique problems for the monitoring and control of draft beer sales. For example, draft beer is usually sold in a standard quantity, such as an eight ounce glass. Frequently, however, a larger quantity of beer, such as a pitcher, is sold at a discount per ounce with respect to the per ounce price of beer by the glass.
Additionally, it is frequently necessary for cleaning personnel to dismantle the beer dispensing equipment for maintenance and cleaning purposes. Therefore, the accountability system must be able to maintain the count through such activity and distinguish between an authorized dismantling for cleaning purposes and an unauthorized tampering or intrusion of the accountability system.
It is also preferable that draft beer accountability systems be compact, since the space in areas where draft beer is dispensed is usually limited. It is especially important that the system be free of any connections to alternating current line voltage, because of the shock hazard potential. Further, while experienced personnel are familiar with the appropriate point to shut the tap off to fill a bear glass or pitcher, inexperienced operators frequently fill the glass unevenly, causing spillage.